The present invention relates to an apparatus and method for filling containers, such as bottles and the like, with a liquid by conveying the containers through a filling machine.
Automated filling machines configured for filling any manner of container processed through the machine by a conveyor or the like are old and well known in the art. For example, a conventional high-speed filling machine typically uses a worm gear or screw-like device to receive containers (i.e., bottles) conveyed in single file and in contact with each other. The worm gear engages each container and spaces the containers apart a desired distance corresponding to the spacing of downstream filling valves. The containers are typically conveyed from the worm gear to a rotating star wheel that receives the containers in individual pockets or recesses. The star wheel may further convey the bottles to one or more additional star wheels, to a rotating table or platform of the filling machine, or may directly convey the bottles under the heads of the rotary filling machine. Examples of such filling machines are described, for example, in the following U.S. Pat. Nos. 2,666,564; 3,519,108; 4,053,003; 4,588,001; 6,253,809 B1; and 6,474,368 B2.
With the device according to U.S. Pat. No. 4,567,919, the containers are spaced apart on a conveyor by a pair of parallel screws and conveyed on the same conveyer directly to the filling valves of the rotary filler without the use of a star wheel.
U.S. Pat. No. 5,029,695 describes a star wheel having a plurality of circumferentially spaced orienting devices around its periphery. Each of the orienting devices includes moveable fingers which can readily assume the contour of different containers. However, the containers must still be indexed prior to being conveyed to the star wheel.
Conventional rotary filling machines of the type described above used in modern high-speed processing lines require relatively sophisticated drives, gearing, and control systems for ensuring precise coordinated movement between the different in-feed and out-feed star wheels, worm gears, and so forth. Also, the star wheel assemblies take up valuable floor space. A typical star wheel may be, for example, 4 feet in diameter. The star wheels also require maintenance and upkeep, and generally add to the overall cost of the filling operation.
Conventional rotary filling operations also generally process the containers in a single file or row through the filling machine, primarily due to the indexing functions of the worm gears and/or star wheels. To accomplish multiple parallel row filling operations with conventional star wheel indexing technology would require complicated and expensive gearing and drive arrangements and is not considered commercially viable. Multiple row filling is thus often provided by linear-type filling machines as described, for example, in U.S. Pat. No. 5,878,796. In this linear design, the containers are typically conveyed serially as a group into the filling machine and captured or indexed into position under filling nozzles or orifices. The containers are typically held fixed and motionless while they are filled. Once the containers are filled, the indexing mechanism releases the containers and the filled containers are conveyed out on the same conveyor and another grouping of containers in indexed into position for filling. The linear-type machines, however, also have drawbacks, particularly with respect to processing speed. The basic architecture of the rotary system design is clearly superior with respect to potential through-put of containers as compared to the linear systems. Also, the rotary systems make far more efficient use of floor space.